Xcode has long been installed in the /Developer folder on the Mac. The introduction of Xcode 4.3 in the App Store moved that to /Applications/Xcode.app. This was fine, except a lot of apps assumed that the /Developer folder exists. This breaks behavior to the command line tools such as opendiff. It, however, still exists in the Xcode.app bundle.

Check out the current path in the Terminal by entering xcode-select -print-path. In my pre-4.3 setup this prints “/Developer”.

It is a simple switch to move this path to the location inside of the bundle.

sudo xcode-select -switch /Applications/Xcode.app/Contents/Developer/

Enter your Admin password and you should be good to go utilizing those command line utilities.